I think that hot permit is required for this purpose.
In this process, this is to spark ,flame and passionate surface appear on possibility.
other precautions:
1. When the job, operator must wear the dust prevention gauze mask and protect a glasses ;
2.Before sand blasting,check the ventilation and dust extraction equipment and start it ;
3.Closen the door and windows of the sand blasting room;
4.Before switch on the sand control, switch on the compress air .And before switch off the compress air ,switch off the sand control.